Two-stroke-cycle internal-combustion engine.



. c. A. HALLBACK. [WU-STROKE CYCLE INTERNAL COMBUSTION ENGINE.

APPLICATION HLED MAY 10. I911- 7 Patented Sept. 17, 1918.

Invento C'u/QHaZ Z/b 510/1 m: NORRIS PEYERS 0a,. Pmzm-uma, WASnINGmN. u a

GAlRL AUGUST HALLIBKCK, OF H E'SSLE'H'OLM, SWEDEN.

To all fiom z't may concern." Be it known that I, CARL AUGUST HALL BACK, citizen of Sweden, residing" at Hessleholm fin Sweden, have invented certain new and useful "Improvements in TWO- Stroke-Cycl Internal Oombustion Engines, of which the following is a specification.

This invention relates to two stroke cycle internal combustion-engines, the object of the invention being to provide a'n-engine-of said class havin its cylinder cover placed between the piston and the crank shaft in order to make the combustion pressure upon the piston to act in a direction from the crank shaft in such a way that the pounding action on the engine bed is totally avoided.

A further object is to provide an internal stance, when the piston 7 has passed half of combustion engine running noiselessly and without shocks, and a still further object of the invention is to entirely dispense with the water cooling arrangements hitherto needed for engines of this class. 1

-lVith these and other objects in view, the invention consists in certain novel features of construction and arrangements of parts, as will be more fully hereinafter described and pointed out in the claim.

For a full understanding of the invention and the merits thereof, reference is to be had to the accompanying drawings, in which;

The figure is a central vertical longitudinal sectional view through an engine embodying my invention, parts being shown in elevation, and parts broken away.

Referring to the drawing the cylinder' l carried by the engine bed 2 is openin both ends and internally provided with an annular bottom 3 inclosing a thinner portion 4; of the piston serving as piston rod and having packing rings 5 or the like facing said portion. In the portion 4 which is hollow for the sake of cooling and open in both ends the connecting rod 6 is journaled. At the upper end of the piston IOCl4l and above the bottom 3 the piston 7 is fastened and fitted into the cylinder 1 with packing rings 8. On the other side of the bottom 3 another piston 9 is fastened to the piston rod 4 and this latter piston is fitted into a prolongation of the cylinder 1. A feed pipe 14 for the fuel and ignition chamber 15 or the like lead to the cylinder 1 near the bottom 3 and the cylinder is also provided with an exhaust opening 1.6 which covered by the piston 7 but will be opened when said piston arrives Application filed May 10, 191 7. SerialNo 167,729.

Two-sTnoKn-oYc n rnrnnnaL-coivrnnsrron nema V Specification of Iietters" Patent. S613). 1 7

to the position most remote from the bottom 3.

' The suction valve is placed directly on "the cylinderwall close to the bottom 3 at the side of the latter n'ea'rest't'o" the crank Shaft. The working cylinder communicates with thespace between the'bottom 3' and the piston 9'by'means-of'a number ofgrooves 17 m the surface of the piston rod 4'. These grooves are'placed inthe end of the rod nearest to the piston 9 and have such a length and are so arranged" that the'conn 'IIlUlllCfltlOIl between the working cylinder and the space on the other side of the bottom 3 always is opened shortly after the piston during it working stroke has commenced to open the exhaust 16 or, for inthe exhaust opening.

By means of this simplified arrangement the-air is drawn through the suction valve 11 into the space between the bottom 3 and the piston 9 during the compression stroke and "at the same time saidv space does not communicate with the working cylinder. The air thus drawn in during the compression stroke will then be compressed during the working stroke, and when the piston has commenced to open the'exhaust 16 the grooves 17 will open the communication between the working cylinder and the space between the bottom 4 and the piston 9 so that the compressed air passes into the cylinder and expels the rest of the exhaust gases. In this way the scavenging of the cylinder will be effected very thoroughly as the air is forced to pass the entire interior of the cylinder before it escapes through the exhaust opening. The arrangement; of the grooves 17 in the piston rod is also adapted to cause an increased cooling of the cylinder and'especially of the packing between the bottom 3 and the piston rod. Further, an engine of this typemay be produced very cheaply as the whole air chamber and its ports are dispensed with.

In order to reduce the possibility of the warm) air reentering the passage or bore of the pistons after being expelled therethrough, said passage is contracted in'such manner that the increased velocity of the air While passing fromthe entrance to the exit will be suflicient to eject it beyond the influence of the-suction created as the piston moves in the opposite direction.

The piston 7 may be fastened to the piston rod 4 by means of screws or the like in order to make it easier to mount the engine.

It is evident that this' type of engine may be built horizontally as-well as vertically.

Having thus described the invention; 'what I claimas new and desire to secure by Letters' Patent is servingto divide Said cylinder into a work-' ing chamberand an .air chamber, an air. supply valvestructure leading into the air chamber upon one side of the annular partition, a fuel conduit leading into the work-V ing chamber upon the opposite'side of the annular partition, hollow pistons operating within the working chamber and air chain- I ber having outer bores of'theeame diameter and inner bores of different diametersg. hollow piston-' rod conneotingfsaid' hollow pistons with its bore contracted at the end which'is adjacent the piston having the smaller bore, said hollow piston having adapted to establish communication between the air chamber and the working chamber, and apitman connected with the hollow piston rod. Y

In testimony whereoL -l have signed my name tothis, specification 1n the'presence of .two subscribing witnesses. r

CARL AuGusr HAL lioK, Witnesses:

A. W. ANDERSON, v {FRED FLERoN,

' 50mb! a: this patent mav be obtained for five cents each byeddre'sai ng the Commissioner of Intern,

- Washington, D. 0.? r v 25 longitudinal exterior" grooves which =-are 

